Test Methods for Driven Piles

Design assumptions only become reliable once a pile has been tested. This chapter explains the main ways to find out what a driven pile can carry, how each method works, and where it fits on a project.

It begins with an overview of why and when piles are tested, then covers static load tests in detail. Static tests are the traditional reference for pile capacity, and the chapter explains how they are set up, loaded, read, and interpreted, along with their cost and time requirements.

A section on Statnamic testing covers rapid load testing, which applies a controlled force to the pile in a fraction of a second and measures the response. You will see how it differs from a static test and what it can and cannot show.

The last section covers dynamic measurements and analyses, the methods that use instruments on the pile while it is being driven. It explains what is measured, how the results are analyzed, and how they help verify capacity, check hammer performance, and find damage.

If you write specifications, the chapter helps you choose the right test and the right number of tests. If you build or inspect piles, it helps you understand what the results mean. The goal throughout is to connect the number on the test report to the load the pile will carry in service.

In this chapter

• Overviewpage 383
• Static Load Testspage 383
  • Prerequisites for Static Load Testing
  • Advantages of Static Load Testing
  • When to Perform a Static Load Test
  • Effective Use of Static Load Tests
  • Application of Test Load
  • Jacks and Load Cells
  • Pile Head Displacement Measurements
  • Types of Axial Load Tests
  • Conducting Load Tests
  • Interpretation of Axial Load Tests
  • Tensile Load Tests
  • Lateral Load Tests
• Statnamic Testingpage 400
  • Overview of the Testing Apparatus
  • Instrumentation
  • Theory of Operation
  • Lateral Load Testing
  • Other Considerations
• Dynamic Measurements and Analysespage 405
  • Background
  • Dynamic Testing Equipment
  • The Case Method
  • The CAPWAP Method (CAse Pile Wave Analysis Program)
  • Application of Dynamic Testing Methods
  • Presentation And Interpretation Of Dynamic Testing Results